Hydraulic power press control



June 10, 1947.

H. P. L. LAUSSUCQ ET AL HYDRAULIC POWER PRESS CONTROL Filed Feb. 20, 1943 5 Sheets-Sheet l :1 muentou Harry I? 1.. Laussucq Bertrand japikse their (BMW June 10, 1947.

H. P. L. LAUSSUCQ ET AL HYDRAULIC POWER PRESS CONTROL Filed Feb. 20, 1945 5 Sheets-Sheet June 10, 1947. H. P. LAUSSUCQ ET AL 2,422,104

' HYDRAULIC POWER PRESS CONTROL fi l/FRY R4 Lib-960w, BERT/VINO JZP/ MSE,

June 10, 1947. H. P. L. LAUSSUCQ ET AL/ 2,422,104

HYDRAULIC POWER P"RESS CONTROL Filed Feb. 20, 1943 5 Sheets-Sheet 4 June 10, 1947. H P. L. LAussuc ET AL 2,422,194

HYDRAULIC POWER PRESS CONTROL Filed Feb. 2 0, 1943 5 Sheets-Shet 5 Patented June 10, 1947 2,422,104 HYDRAULIC POWER PRESS CONTROL Harry P. L. Laussucq, Reading, and Bertrand Japikse, Reifiton, Pa., assignors to Birdsboro Steel Foundry and Machine 00., Birdsboro, Pa., a corporation of Pennsylvania Application February 20, 1943, Serial N0. 476,584

6 Claims. (Cl. 192-138) This invention pertains to a hydraulic power press and more particularly to a stroke control device adapted to limit control or interrupt a downward action of a movable platen beyond a. preset or predetermined degree.

5 the lines 5-5 of Figure 2 looking in the direction An object of the invention is to provide, in a of the arrows. downward acting hydraulic press, cooperating Figure 6 is a vertical sectional view taken along means for rapidly and completely unloading the the lines 66 Of vFigure 4 looking in the direchydraulic system of the press at the time a movtion of the arrows. able platen thereof reaches a predetermined po- Figure 7 is a ertical secti nal V ew ta e alon sition in its downward movement so that a conthe lines 1--! of Figure 6 looking in the directinued downward action of the platen is defition of the arrows. nitely arrested or interrupted. Figure 8 is a vertical sectional View taken A further object of the invention is the proalong the lines 8-4 of Figure 2 looking in the vision, in a hydraulic power press, of a dial ar- 155 d rection of the a rows. rangement having dual pointers, hands or inde- Before reference is made to the drawings in pendently movable means, one of which may be a l, it y e Stated generally that a press manually preset to determine or control definitely of the instant invention, during the first rapid the limit of downward movement of a, movable operation of the press h s a m vabl platen platen. thereof urged downwardly and before the mov- Still another object of the invention is to proable platen contact the work a bracket on the vide an electrical means carried by a dial ar movable platen is arranged to contact a hardrangement and which may be affected upon dual ened washer and from that moment on a rear pointers or hands of the arrangement becoming pointer or hand of the dial begins a clockwise co-radial or coincident. movement around the dial. The action of the A mor detailed object of the invention is the movable platen will proceed until the platen stalls provision of a pressure stroke control in a hyagainst the work. After the operator has satdraulic power press and having a fixed dial with isfied himself that the work is properly clamped a front manually movable arm arranged to be d s p s t a front pointer or hand to a depreset prior to the downward action of a movsired position, determined by measurement of able platen and an additional or rear hand rethe amount of straightening that must be done, sponsive to the downward action of a, movable he will then move an operating lever beyond the platen; both hands being s arranged and confast approach position which will result at the structed that when they are co-radially disposed same time in the tripping of a limit switch wherethere is caused a release of the fluid pressure in by it becomes possible to build up operating tonthe hydraulic power press system. nage. The movable platen will then proceed in The above as well as numerou other objects a downward direction and the rear pointer will of the invention will become apparent from the continue to travel around the dial until it reaches succeeding description taken into consideration a position at which the front pointe 01' hand has with the accompanying drawings which disclose been preset. At this exact moment a sensitive an exemplified form of the invention and wherel ctri wit h is tripped y the dial mechanism in: and the electric circuit is broken to actuate a Figure 1 is a schematic or diagrammatic view valve which is vented to release the pump deor a hydraulic power press embodying the preslivery from the oper ng p mp and at the same ent invention. time releasing the hydraulic pressure in the sys- Figure 2 is a front elevational view of a dial tem. At this instant, therefore, it will be no arrangement embodying a portion of the present longer possible for t e mova le p at n to trave invention arranged to cooperate with hereinafter downwardly since its downward action or described parts of the hydraulic power press il- 5 straightening operation isinterrupted. The eleclustrated in Figure l. trio circuit in the press is so wired that buliding Figure 3 is a vertical sectional View of the dial up pressure cannot be repeated until the operarrangement and taken along the lines 3-3 of ating lever has been actually pulled back caus- Figure 2 looking in the direction of the arrows. ing the movable platen to be raised and thereby Figur 4 is a horizontal sectional view takenmaking it impossible to build pressurewhich along the lines 44 of Figure 2 looking in the direction of the arrows.

Figure 5 is a horizontal view shown partially in plan and partially in section and taken along would be harmful, not only to the work but to the operating mechanism of the press.

Referring now in detail to the drawings, wherein like reference characters indicate like parts, the numeral 1 is employed to designate in a general manner a hydraulic power press which exemplifies the present invention. Considering initially Figure l of the drawings, which, as previously stated, shows a somewhat diagrammatic view of the hydraulic power press, the press comprises a lower or stationary platen 2 having rising therefrom guide columns or posts 3' extending between and secured to a head 1 and the stationary platen. Arranged to move vertically of. the press is an upper or movable platen '5' urged down wardly during the downward stroke of the press by a main cylinder 6 and raised upwardly during the return or reverse action'or'stroke of the press through the medium of pull-back cylinders Forming the upper portion of the press is an overh a n 3 wh ch in he instant i l st ation functions as a combination surge tank and suetion ta s- A o ate iwit he'press and. terminsa rt o the h d aul c s st m s a ma n pump 9 which supplies fluid pressure to the press and has a discharge line it! running to a reliei Valve H When this relief Valve is closed. the flow of fluid from the main pump takes place in the manner as indicated by the arrow into linev I2, through the check valve L3 and then to the Operating valve IA. The operating valve is a'fourway type to permit the flow of fluideither to the main cylinder 6 'from the port l5 thereof. 'to cause a downward action of the movable platen or to the pull-back cylinders 1, from the port. l6 and through the line l1. to causeian upward movement of the movable platen. When the operating valve is set to service the port IF) the opposite port or connection Hi. is exhausted ou h the p 8., hec va ve t, back. pres.-

sure valve 21 into the line'2 i, andoverheadtank.

8. When on'the other handthe operatingvalve is set to service the port I5.,to thus operatethe pu lrb ck. linders, through the port -I8 into'the overhead tarrlgdr The re i a ve standard type and assuch it is belieyed herein n cess ryto l t ate inde a l. oweyenf r.

a m ete. es t on ot heop r tmn off the. pr s nd...pa ii e l he. hy raulic. system.

h epf, it. is m dessentiel t tetethatthei relief valve comprises a Teshaped body Ll (Lhav;

ing pressure connections H band .I la and .a drain connection I id through which; the fluidpressure from n 91bvs d..w en. he el ei;

rve. u lo d d. s wi l e: e e naft e: scribed) into the back pressure valve 29,. line} I and verh ad t nk M e pecific ly, here..-

elv a e eeti t e t m f e. r .ion.

n a relief lve. u ee eee t e e a T e. un e l' a cy 'ndri a1 po ti not the relief valve bodyand} ul e ipairt or the valve through theiuse of La small augniar spring loaded, supplementary re 'er v ve builtin't'o th reher valve I I: variable pressures over th m in plunger are automaticallyregulated to hold the? p'l 'ne et f ie tl n i aw fedeterm blowioff pressure has 'b'eenfreached and then valve will open-up to proportional amounts to automatically alloys it to open sui iicier tl'y to new ofi the ex' e'ssive' fluid pressure "delivered to the relief 'valve falfid" at the full preset pressure in the hydrahlic syst'emi The 7 nature of this relief valve is alsosuchfthat'iffihe pressure connection below theTseatYof the supthe port I5, is exhausted.

H of .a. q nm rcia desi n or same timemaint in'tne 4. plementary relief valve were open to drain through port ild, the relief valve ll would be completely and immediately unloaded or vented in its entirety, thus completely negativing or unloading the pump 9 and thereby releasing all pressure in the hydraulic system through the seat M the valve and through thebottom connection except that the valve is further equipped with a light spring which will always maintain a mini mum pressure in the instant structure of approximately pounds per square inch which is .insufficient'pressure to build up enough pressure in the press to do any. work. 7

' In the pipe line'22 running from port I5 of the'operating' valve to the main cylinder is placed aspe'cial' valvepart 23 which is in the nature of a combination relief valve 24 similar to the valve H and a flow regulating device which might be compared to a plug cock25 with refinements for automatically adjusting the valve so that wh n nce. set up to permit a certaina'mount of fluidto by-pass through the valve to the. main, cylinder the amount of flowwill remain constant irrespective of the. pressure required to be built up in the main cylinder. The plug. cock worksv in conjunction with the. relief valve. 24. in that the relief. valve bleeds ofithrough. thexdischarge connection. of the valve. any excess fluid deliveredrby. the. pump. above the. amount which ismetered through the plug cock portion oL-the. valve. The fluid. thus. byepassed by .therelietvalve portion 24. retur sthrou h valve: Zflback to. the surge. tank and. is therefore wasted. In the diagram thereisshown an outline for the valve body with a plug cock portion. and a relief valve'poi'tion show-n separately'therein. 'This,. however, is done for diagrammatic. expediency. The special valve. part j 23, is, also, equipped-with a small. pilot, orauxiliary relief valve, same. as in the valve lfiwhereby the maximum pressure may be preset and thet Valve can again. be vented. and. then the only pressure, that. can. be developed. in the. systemi's equal to., that, created by. thelight-springJnothQW.1i) h reinbefore mentioned. which gives ap-, proximately 65 pounds persguare inch .backpressure. 'IIhi vaI e, will, permit full. volume. flow only in h forwarddi ec ion .andinordentopermit thefluid te beexhausted .fronrthemain, cylnd x... t. s. 0f. c urse necessary. eece. a. check. a vefit. o, hn es the. regulati and relief.- a veie ha ei rhflew. .rec ion.

It will, be nptedthat. from. this valve 2-3; there isshowne vent. cqnue ti n ich leadsito three. addi ae velve g t a .d T epurpose fal e;

. 'k e lmo a. platen, 'thepress'iireof the spring agains 32 oi the check valveisbuilt up. pro ssiv. elever i d ee ee u ther- ACQOId' P et relief lve. f Preset t i rtiene e tiqeef.

l. u zlwr eeedi wi h the operating. lever and likew se thejlie f valve portion of valve 23 is loaded'ito 'higher-pressnre I settings whentheoperatingflever 3? is 'shi away from'cente'r or 'to lowrpressurs when e lever is shifted "closer "to: center; T The 'iposit if of the operating lever 3| indicate the following operating conditions: When the operating lever is in position B the press platen is raised up at full speed; in position C the platen is stopped; in position A the platen is lowered rapidly to the work but no pressure can be built up on the work,

except the initial 65 pounds per square inch mentioned above. Between positions A and D pressure can be built up on the work but the amount of pressure that may be developed is proportional to the distance that the lever has been shifted between these two positions.

The maximum pressure that can be developed is in addition limited, however, by the relief valve 28 which is a micro-adjustable pilot relief valve and by adjusting the setting of this valve it can readily be seen that it is possible to limit the maximum value of pressure that can be developed by the use of the valve 21.

The hereinbefore described construction and arrangement has, it is believed, been previously employed. However, the introduction into the hydraulic system of the valve 29 marks a departure from the art and which deals with the advancement made over the prior art in that it is definitely associated with or functionally related to the dial control hereinafter described in detail. As will be noted, the valve 29 is connected to the vent system of the valve 23 and its twoway valve permitting flow of fluid to take place from port 33 to port 34 in which case the vent connection is open to the tank or this passage can be blocked by shifting the valve plunger. The connection to the port 35 in this valve is provided. merely to remove slippage of fluid which may have escaped past the valve plunger clearances. This valve 29 is solenoid operated and so arranged that when the solenoid is deenergized the valve is open for flow from port 33 to port 36 and when the solenoid is energized the valve is closed. In view of the above, it will, therefore, be understood that when the solenoid is deenergized the entire pump delivery is being Icy-passed through the vented relief valve portion of valve 23 but as soon as the solenoid is energized the pump delivery is no longer by-passed but is then directed towards the main cylinder for the purpose of building pressure therein and this pressure can be built up to the value predetermined by the amount of loading on valve 27 but within the limitations made by the setting of valve 28.

A limit switch 36 is provided in the press for the purpose of energizing the solenoid of valve 28 and is so mounted that when the operating lever is moved the first initial distance beyond position A toward position D its circuit is closed thereby energizing the solenoid through relays (not shown). The valve 29, therefore, is closed at the moment that hydraulic pressure is being built up.

The hydraulic power press is provided with a dial control generally designated as at 31 which presents a control means whereby the circuit of the solenoid in the valve 29 can be broken instantly when the movable platen has traversed a predetermined distance. For this purpose the dial control mechanism will trip at that moment a micro-switch 38 (see Figures 3 and t). The means by which this micro-switch is operated will be described hereinafter but for the present consideration it will be assumed that the movable platen has caused the switch to be tripped and the solenoid to be deenergized. The effect will be that the relief valve portion of the valve 23 will be instantly vented through ports 33 to port 34 in the valve 29, thereby disturbing completely 6 the balance of valve 23, the latter of which will then open instantaneously and by-pass the pump to exhaust the high pressure out of the hydraulic system of the press thus stopping or arresting the further downward travel of the movable platen. By making use of a device which unloads pressure by instantaneously unbalancing a valve plunger there is obtained a much faster action than if there were merely operated a piston type of valve by electric means because such a valve of the latter type generally has long laps which must be uncovered before the valve opens and of course, in such instances, some additional pressing work would be done while this uncovering of laps takes place, thereby materially increasing the amount of over travel which would be reflected in the press.

Referring now in detail to the dial control mechanism 31 illustrated in minute detail in Figures 2 through 8 inclusive, there is provided a supporting plate 39 angular in vertical cross section having a vertically disposed leg 39a which is secured to the stationary or lower platen by any desired means and a horizontal leg 39b forming a shelf for the support of the dial control mechanism. Mounted upon the supporting plate in fixed relation thereto is a control box ii] comprising a bottom plate 46a superimposed upon and secured to the horizontal leg by any desired means and joined top and side plates Nb and M30 respectively. Extending between the top, bottom and side plates and secured thereto preferably by means of welds are front or face and rear or back plates 40d and ite respectively and which are vertically disposed and in horizontal spaced relation with respect to one another. Disposed within the control box desirably centrally thereof is a tubular element or ferrule 40f secured to the front and rear plates by means of welds to rigidify the box against stresses to which it will be subjected in service. The front and rear plates are provided with horizontally aligned circular apertures 469 in axial alignment with the ferrule for the accommodation of a hub M which has a head Ma outwardly of the front plate and secured firmly thereto and a shank llb extending rearwardly from the head and arranged to fit neatly the aligned apertures g. Disposed within the hub and arranged to rotate therein is a main shaft 42 tubular in formation and thereby provided with an axial bore 42a extending entirely therethrough. Horizontally spaced bearings $271 are circumam-bient the main shaft and housed within the confines of the hub to maintain the main shaft in a predetermined or relatively fixed radial disposition. I

Spaced forwardly of the control box is a washer-like disc or dial 43' preferably circular in formation having a central opening 43a and retained in position by means of quadrantly disposed brackets :l. Each bracket desirably comprises a foot Ma firmly secured to the control box front plate and having extending therefrom a stem Mb terminating in a re-entrant flange nto welded or otherwise secured to the front face 432) of the dial to hold the latter rigid. Keyed to a shank til) which forms a continuation of the main shaft and projects through the extended plane of the dial is a sleeve 45 arranged to respond to or move with the main shaft. Journaled to the sleeve and arranged to be moved manually relative thereto is a setting hand or outer or front pointer or marker 43 which has a bushing 46a thereof neatly fitting the sleeve and retained in journaled relation therewith by means 7 or a locking nut 41. Forming the main portion. of the setting hand or marker is a setting hand bar 4'61) of. rectangular formation and arranged to extend across. themajor portion of the station.- ary dial. The setting hand is provided with an adjusting hand 48. of substantially the. same. shape as the associated portion. of the setting hand bar and has formed atone end thereof a hinge. butt @800; which mates with a hinge. butt 450 formed on the setting hand bar. A. pin d extends through the half hinges or hinge butts and thereby provides a pivotal connection between thesetting hand and adjusting hand. A housing 49. is formed on the adjusting handtoextend outwardly therefrom in a direction away from the setting hand and is provided with an opening 4% which is covered by a transparent pane i -9b so that dust;

dirt or any other foreign particles may be excluded from the mechanism encased in the housing which will be hereinafter described, as well as present a port through which the mechanism may be viewed for inspection purposes. The extremity removed from the hinge butt 48a of the adjusting hand is formed as a bifurcated lip 48?: which accommodates a portion of a pin 430 to be pivotally connected thereto. A shank 48d of the pin extends through a suitable or aligned aperture in the setting handto terminate in a finger iS'e projecting inwardly of the dial control and into the plane of the stationary dial. As will be-no-t'ed by referring particularly to Figure 2 of the drawings, the dial is provided with graduations or indicia means adjacent its periphery and in radi'ai alignment with each graduation towards the center of the dial therefrom is an aperture ite to present a series of equally spaced or circularl'y arranged apertures extending completely around the stationary dial; The apertures 46c accommodate the finger 48c so that the assembled setting hand bar and adjusting hand. may be maintained in a predetermined position such, for example, as horizontal as illustrated in Figure 2 of the drawings. and for the purpose to be hereinafter explained; Since the apertures beneath the setting hand are obstructed from View the adjacent extremity of the setting hand bar is pointed as at- 46' so that an operator may align the pointed extremity with a particular graduation" in the course of making his setting. The setting hand bar and adjusting hand are maintained' in. juxtaposition by means of a sleeve 50' secured"- to and outstanding from the adjusting hand and which houses a spring means such as the illustrated coil or helical spring 5801.. The helical. spring has its inner extremity bearing against the adjusting hand while its outer extremity reacts against a head. b of ascrew 50c,

the latter of which extends through the spring and adjusting hand to be anchored in the setting hand b'ar. An operating handle 5i is providedon' the adjusting hand so that the latter may be urged away from the setting hand bar about the pin Mal-t0 withdraw the finger from a. particular aperture duringthe process of rotat ing. the setting hand; front pointer or marker to a. difierent location or disposition. A similarly designedoperating' handle. Elaz'is: arranged tooutstand;from adjacent the-setting handiextremity removed from the pointedzend so that in the course of. making a setting both handles 5| and 5111 may." be employed;

Disposed inwardly: of." the: stationary dial in parallel spaced. relation thereto; is an. indicating hand or inner. or; rear. {pointer or marker 5 zzwhich. is: sec uredtoand; forms; a part; of; the: sleeve 4%; 7.5

8" so aslto be also responsive to the. rotarymovement of the mainv shaft 42.. The. indicating hand has a'taili portion 52a which acts as a counterbalance therefor and projects. radially from the. sleeve. In radial alignment with. the. tail portion is a branch 52th which has a. free extremity 520 of u-shaped; formation extending about the outer edge of the. stationary dial. to: terminate in. a restrictedv portion. or end. 5211. positioned in spaced relation to the front faceof the stationary dial as clearly indicated in Figures 2 and 3. The rear pointer is provided with a trip peg 5 3 which is positioned intermediate the sleeve and U-shaped extremity of the indicating hand and'isithreadedly associated therewith so as to-be adjustable transversely of the dial control. Ajamb nut 53% is threadedlyassociated with a trip peg so as to retain the latter in a fixed position. The trip peg has a free extremity 53b thereofexten'di-ng into theprojected planeof the stationary dial and into the central opening 23a so that the indicating hand may rotate unrestrictedly throughout its entire range of rotary movement. Equally spaced from the axis of the main shaft is an operating pin 54- carried by a guiding nipple 56a which is secured toand, forms an integral part of the settinghand bar. The guiding nipple extends through an opening 48' in the adjusting hand to a desired location, the trip peg extremity 53h will engage the operating pin extremity see and cause the operating pin to be shifted outwardly of the guiding nipple or displaced from normal position.

Firmlysecured to the setting'hand bar and also extending through the operating handle opening 48 into the housing at a'loca'tion toward the main shaft from the guiding nippleis a triplever' clevis 5a which is' pin -connected to a triplever 55a intermediate the ends of the trip lever; Qne;

, extremity 55b of the trip-lever. isdisposed in asuitable' slot of the guiding nipple and bears against an associated extremity of the operating pin so that any outward movement of theopera-ting pin will be reflected in the trip lever. The

i trip-lever from the clevis extendsacross an ex tended plane of the main shaft tohave its opp'o site" end 550 pivotally connected toaguide pin or plunger 55d which is heldin adefinite path by means of a cup 556 secured to and forming a part of the setting hand bar toalso; extend into the housing through the adjusting hand opening; Associated with the main shaftis aswitch'operating. rod 56 having a head 56min: abutting rela;- tionor intimate contact with the triplverfida; and retained in such a position by meansof a. coil. spring. 561'). encased :by themain shaft. and tending to urge the redhead outwardly: therefrom. Theswitch operating rod 56 has-a stemthe extremities. of." the trip' peg and operating pin come. in contact with one another the switch operatinglrodithrough' the displacing action of the trip: lever will be urged through: the-main shaft to trip the micro-switch, thus breaking the circuit in the solenoid valve 29 to result in the instant arrest of a continued downward movement of the movable platen.

Means has been provided to rotate the main shaft and indicating hand so that it may rotate from the zero or vertical position as indicated in Figure 2 in a clockwise direction until the trip peg contacts the advanced operating pin to trip the microswitch. For this purpose, there fore, there is provided a stroke control bracket 51 which is attached to and carried by the movable platen 5. The bracket is provided with a vertically disposed bushing lined orifice 51a arranged as a guiding medium for a vertical extension rod 58 which has a lower extremity fitting snugly into and firmly secured to an associated extremity of an operating rod 59. Surmounted upon the operating rod and circumambient the extension rod is a hardened washer 5811 against which the bracket may strike upon a downward movement of the movable platen. As will be understood, the proper distance between the hardened washer and bracket is determined when the movable platen is at normal position and the indicating hand is at rest at zero or as shown in Figure 2. The operating rod is maintained in a predetermined path of travel by means of a guide bracket 59a rigidly secured to or mounted upon the control box top plate lib. The operating rod is provided with a slot 591) extending transversely therethrough intermediate the ends thereof for the accommodation of a shoe 590 which is mounted on or secured to the control box back plate Me. The shoe not only acts as a guide medium but also prevents the operating rod from rotating about its axis. The operatin rod extends down to the area of the control box bottom plate where its lower extremity projects through, in sliding relationship thereto, an adjusting nut 56d which is threadedly associated with an adjusting nut bracket or leaf 596 secured to the bottom plate of the control box. A stop or locking pin 59 removably secured to the control box bottom plate has an extension 59g thereof which extends into a suitable orifice of the adjusting nut to retain the latter in a fixed position. Shims 59h are employed to position the locking pin so as to accommodate the particular vertical setting of the adjusting nut. A castle nut and hardened washer 59d are threadedly associated with the lowermost extremity of the operating rod to abut the adjacent portion of the adjusting nut. Mounted beneath the shelf 3% of the supporting plate is a limit switch 60 which has an arm 60a extending therefrom and positioned in the path of travel of the operating rod so that as the movable platen travels downwardly sufliciently to cause the bracket 5'! to bear against the hardened washer 53a and urge the operating rod downwardly, the switch 60 will be tripped to prevent an overtravel of the movable platen under operating tonnage which, if not arrested, would cause damage to the dial and other parts of the press. This limit switch, therefore, operates relays (not shown) so that it too may cause solenoid 29 to become deenergized and thereby the movable platen can no longer be forced downwardly under hydraulic pressure. By a manipulation of the castle nut the operating rod may be adjusted to the exact position in order that its exact location may be set up on the press to obtain a predetermined travel at the desired elevation.

Removably secured to the back plate of the control box is a gear guard 6| which forms a shield for a train of gears Ma housed therein. Carried by the back plate of the control box is a stud Bib which has freely and rotatably associated therewith an operating sprocket '6 I0 which extends partially into slot 591) of the operating rod. Draped over and in operable engagement with the operating sprocket is a roller chain Gld having one end thereof tangentially disposed relative to the sprocket'and desirably common to the axis of the operating rod. A short distance below the referred to extremity of the roller chain is a bridge Ble formed in the slot of the operating rod and presenting an anchorage for a connection Glf which presents a means for tying the roller chain extremity to the operating rod. Accordingly, any downward movement of the operating rod will be reflected in the roller chain to cause a clockwise rotative movement of the operating sprocket. Disposed below the plane of the stud Bla is a similar stud 62 mounted on the rear plate of the control box and carrying a relatively rotatable compound sprocket 6211 which comprises a chain sprocket 62b and a relatively larger gear 620. The roller chain is intermeshed with teeth of the chain sprocket and wound partially therearound to have its adjacent free extremity firmly fastened to the chain sprocket. Accordingly, any rotative action of the operating sprocket in a clockwise direction will, through the roller chain, cause the compound sprocket to rotate about the stud 62 in a counterclockwise direction. is a pinion BM in intermeshing relationship with the gear 620 so that if thelatter is rotated in a counter-clockwise direction the pinion will be rotated in a clockwise direction to result in the main shaft and indicating hand being rotated in a similar direction. A downward action of the movable platen will, therefore, toward the end of its downward movement, cause a rotative movement of the indicating hand and result in the trip peg contacting the operating pin for the above explained purpose.

Means has also been provided so that upon the completion of the straightening operation and the movable platens return to raised or normal position, a reverse movement will be set up in the main shaft and related elements to also return the indicating hand to normal position. To accomplish the above, the main shaft in the rear of the pinion is provided with a sheave 63 which is keyed to the main shaft so as to move therewith. Mounted on a micro-switch support 63a below the plane and to the one side of the main shaft is a roller bracket 63b supporting a freely movable roller 63c. Supported by thebottom plate of the control box beneath the roller is a shield 66 comprising a web plate 54a secured to the control box and having extending therefrom in opposite directions a tube 641). Disposed within the tube and arranged to move relatively thereto is a top clevis 54c. Wound about the sheave and having one end firmly secured thereto is a cable 5412 which trails over the roller and extends down into the tube to have its other end secured to the top clevis. The lower portion of the top clevis is provided with a cross pin 64a to which there is secured top extremities of coil or tension springs 54]. The lower extremity of the tube has, closing the clear opening thereinto,

an apertured barrier 649 through which extends a bolt 64h depending from a bottom or lower clevis 6G7. The bottom clevis is likewise provided Keyed to the main shaft '11 w t a cross pin We towhich a e anchored th l wer ex remitiesof thesprins 1: 4}- An adjust- .inewmeansor not Mat is th eadedly associated anism to norma position, as clearly indicated in: Figure .If afterthe hy raulic yst m has been a t ated: to returnthe movable pla en o normal oosi tion it is determined hat an insuffic e am of'travel has been effec ed i the mov b e pl en to strai hten comp ete y he work, the: settin location. with the distance advanced being det r nuned bythe amoun of ad itional movable platenactionreduired to s raighten he w r a then the operatinscycle of. the pr ss. can be initiated oncemore,

From the above i will b not d that ar o chan esnalld alterations may be m t the her in descr bed illus rated c s ruc i without d parting: from wit n the spirit of. the invention and the-scope of th appended claims.

We claim:

1. a pressure, stroke control of. a hydraulic power-press .t ecombination of, a dial. a rotatable pointer arr ng d to be maintained fixed with respect to sa d ial, pivo m ans c r i by-sai rotatab e 1 93 31 12.? second; Po nt r arran ed to respond'to a downward ac ion of a va le pla .orsaidrzress, means fi ed r lativeto said second pointer andr an ed to c ntact said piv tal means, cansac ua e -by sa d pivotal means for limiting the. downward action f aid movable platen, and means connocted to said second pointer for r turningthe lat er to normal l ti-on.

2; In a hydraulic power press having. a ui opera-ted movable. platen, the'cornbination of, a solenoid. operated: valve, amovable pointer arranged tobe fired at: a. predeterm n d po iti n,

a seoond' pointer responsive-to the downward action of a movable plat n-,. pivotal mean carried by one of said pointers, afixed means carried by the other of said pointers, said. pivotal and fixed. means. beingadapted to contact one another upon. said movable. and second" poin r reaching av predetermined-- relationship, and means actuated by said pivotal means-for deener izin said sol noid ope atin s d v l e a thereby causin an interru ti n i h do nwa d ction of said mo able platen... I

e; Ina; hydraulic power press; havi a fl op ratedmovable late the ombination of, a solenoid: operated v e, a d al, a v e p i t r arranged, to be fixed with respect-to said dial at a; pr det rmined p siti n. a s c nd. po n r r snonsive o the downward action of s id mo a l platen; pivotal me ns carried by one f said pointe s; a .fiaedmean carried by the. ot r of said. pointers, aid pivotal and. fixed means being adailtedxto conta t ne another pon said movbl and s ond p int rs rea hing a predeter mined relationship,means actuated by said pivotal meauis for-deenergizing said solenoid oper. ating said valve and thereby causing aninterruption'inthe downward action of said movable platen, and means energized upon a downward action of said movable platen arranged to return said second pointer to normal position upon a raising action of said movable platen. l

.4. In a pressure stroke contrlf a hydraulic power press, the combination of, a stationary dial, a shaft extending through said stationary dial, a manually movable pointer disposed" on one side of said dial and journaled to said shaft, a secondpointer disposed on the opposit side or said dial and fixed with respect to said shaft, means actuated by a downward action of a movable platen of said press for rotating'said shaft in one direction, means energized by saidqdownward action of said movable platen for rotating said shaft in an opposite direction upon an uphand can. be adva ced ar und th dia t a new 7 ward action of said movable platen, and means associated with said pointers adapted to contact one another for causing a release in fluid pressure causing the downward action of said movableplaten.

5. In a hydraulic power press having a, fluid operated movable platen, the combination of, a

solenoid operated valve, a pointer arranged to be fixed at a predetermined position, a second point- .er responsive to the downward action of a movable platen, means carried by one of said pointers, means carried by the other of said pointers, said pointer carried means being adapted to contact one another upon said pointers reaching a predeterminedrelationship, and means actuated by said firstnamed means for deenergizing said solenoid operating said valve and thereby causing an interruption in the downward action of said movableplaten.

6; In a hydraulic power press having. a. fluid operated movable platen, the combination of, a solenoid operated valve, a pointer arrangedto be fixed at a predeterminedposition, a second pointer responsive to a downward action of said mo able. platen, and means c r ied by both of a d pointers and adapt d to contact one another up n a d p nt reachine av p rmined relationship to result-in the, deenergizing of said solenoid operating; saidvalve and cause an interruption in the. downward action of said movabe platen.

RRY L- A SSUCQ, BERTRAND JAPIKSE.

REFERENCES .crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS 

